NCG 7635 - The Bubble Nebula
The Bubble Nebula, in the constellation of Cassiopia, lies within a cloud of glowing hydrogen gas 11000 light years away. Gas is being given off by a large star within the bubble but is being constrained by the surrounding gas and interstellar wind to form the bubble. The Bubble itself is about 10 light years across.
This image was taken using Ha and OIII narrow band filters and artificially creating a green channel to form a colour image.
Date:2 nights in December 07.
Location and conditions: Back garden, Mag 4 sky. Seeing good but thin high cloud often reducing the transparency.
Scope: Skywatcher ED120.
Camera: SXV H9.
Other equipment: Tak EM200 mount, SXV guidehead, Truetek motorised filter wheel and Astronomik 13nm Ha and OIII filters.
Capture and processing details: 7x20mins Ha and 4x20mins OIII (The second night was terminated by cloud so not as much OIII as I would have liked - this is UK imaging, we have to be realistic!). Captured and combined with Maxim DL The Ha was used as the luminance channel. The Ha was mapped to red and the OIII to blue. I used Noel's Astronomy Tools to create a synthetic green channel in PS. So I guess this is HaHaOIIIsynth green.